So how does the 2013 logo differ from the previous few years ones?
1. No numbers. It's in roman numerals.
2. Out of all the years I have shown only only 2007 and 2013 have not had a little catch phrase to go with the logo.
3. Every year I have shown since 2008 have shown the iOS square app pics. Maybe this is a hint that iOS 7 will be talked about this year.
4. There is no Apple in the logo. Not every year has featured the Apple. But I am sure the choice not to feature the Apple was chosen for a reason.
5. Different font used as many people have said.
6. The first year I have noticed where the "WWDC" part is not in bold type. it is in plain font, the same as the year.
7. The font itself has colour. Well the MMXIII part does. Every other year has been either black or white. Neither of which are a colour.
8. Apple feel the need this year to say it's the Apple WWDC. They didn't even say the Apple word in the years past. I'm sure this has to do with the fact the logo is not an Apple. But maybe there is more to it.
And more and more.
What do you all think?

I believe the typeface on the iPhone 5 box is Myriad Pro Light. The typeface on the WWDC poster is Helvetica Neue UltraLight.

Interesting. Just a note that roman numerals are normally used when describing the year a movie or television show was produced.

What's funny is that we're all astounded by the new logo. lol You have done it again Apple.

Wouldn't mind some of that colour back in the old Finder sidebar

It is definately a watch. The colors represent the many colors it will be available in. The Roman numerals are there because the earliest timepieces such as sundials had Roman numerals. The sundial was the revolution in telling time. I think Apple is using Roman numerals like found on sundials to suggest another revolution in telling time.

I think the roman numerals indicate that Tim Cook has been on a mission in the ancient roman era using the new iTime time machine...He has been helping the Julius Caesar administration deploy iPads....

One of the main causes of the fall of the Roman Empire was that, lacking a zero in their number system, they had no way to indicate the successful termination of their C programs

Good lord what I could have been if I was born in the 90's with a PC in my crib

OMG, we can only wish.... he should do it with Billy Corgan, they can plan the future together...

It means Jony Ive just dropped acid.

The number at the bottom of the logo can only mean one thing. Apple is skipping OS XI and XII and going straight to XIII.
That will show people who say that Apple needs to innovate more!

... Touche.

Umm, I think he was being facetious.

my preeeecious, 's gonna be annouuunced, my preeecious

...... iveOS 7..... We have been expecting you !

The logo clearly suggests Apple will be launching AirPort expresses in multiple colours.

The un-Apple-y-ness of that WWDC logo has really jiggered my flim-flams.

Appropriately it’s a review of a film by a director Mr. Ebert held in great esteem: Terrence Malick. Of Malick’s last film, Mr. Ebert remarked: “There were once several directors who yearned to make no less than a masterpiece but now there are only a few. Malick has stayed true to that hope ever since his first feature in 1973.”